1. Field of the Invention
Generally, the invention relates to small light bulbs. More specifically, the invention relates to such light bulbs suitable for use in conventionally known pen light flashlights where a portion of the bulb proper acts to focus and direct a beam of light utilizing optical focusing qualities contained entirely on the bulb.
2. Description of the Prior Art
Pen light flashlights produce a beam of light wherein the bulb contains structures which focus the produced light into the desired beam. The discussion of the prior art will be limited to these types of flashlight, and applicable bulbs which are sometimes referred to as lamps.
There exist three mounting methods for pen light bulbs within conventionally known pen light flashlights. A first method of mounting the bulb within the pen light flashlight involves providing threads within the housing of the pen light flashlight which receive threads positioned on the bulb. This type of mounting generally provides for proper and true alignment of the bulb within the pen light flashlight wherein the axis of the beam of produced light aligns with a central axis of the pen light flashlight. One major disadvantage of this type of pen light flashlight involves an increase in production costs associated with fairly precise production of the threads within the housing of the pen light flashlight. A second method of mounting the bulb within the pen light flashlight involves utilization of the typical mounting method used in conventional collimating flashlights wherein a relatively wide rim on the bulb is held between two securement structures of the pen light flashlight. Typically these two securement structures will involve opposing threads which cooperate to trap the bulb between two radially disposed trapping surfaces. One major disadvantage of this type of pen light flashlight also involves an increase in production costs associated with fairly precise production of a set of threads within the housing of the pen light flashlight and fairly precise production of a ring member with a set of threads thereon. A third method of mounting the bulb within the pen light flashlight involves retention of the bulb utilizing a pressure bearing contact of the bulb against a portion of the housing of the pen light flashlight. Pen light flashlights which use this pressure bearing method of mounting have the advantage of being inexpensive to manufacture when compared to pen light flashlights which utilize either of the other methods of mounting of the bulb.
The pressure bearing contact method is the method applicable to the present invention and typically involves providing a radially disposed inwardly facing seating surface situated about a terminal end aperture upon which a transparent end of the bulb rests with a focusing portion of the bulb extending outward through the aperture. A spring member typically applies the pressure. This spring is either positioned between the bulb and a battery or behind the battery, or batteries, with the battery in contact with the rearward end of the bulb.
The pressure bearing contact method has several disadvantages when conventionally known pen light bulbs are employed. Pen light bulbs typically do not have wide lips on the metallic housing adjacent the transparent protective cover. Therefore the pressure bearing contact must occur against the transparent protective cover. These conventionally known bulbs are designed with a fairly long narrow portion at the outward extent of the transparent protective cover where the optical focusing portion is located. This contour arrangement provides for an extremely unstable mounting of the bulb wherein tipping may easily occur. Additionally, the base of conventionally known pen light bulbs have a relatively small diametric measurement. This small size of the base is even more pronounced when threads are positioned on the pen light bulb. This narrow base tends to increase the tendency of the bulb to tip out of alignment with the central axis of the pen light flashlight. This tipping tendency is even more pronounced when the spring is positioned against the bulb, which is the most common placement position.
As can be seen various attempts have been made to provide for a pen light bulb which may be utilized within conventionally known pen light flashlights. Typically, manufacturers are willing to accept that the axis of the beam of projected light does not match the central axis of the pen light flashlight proper. Previously, it has been necessary to increase production cost by utilizing a more complicated housing design in order to eliminate the out of alignment beam of projected light. These attempts have been less efficient than desired. As such, it may be appreciated that there continues to be a need for a pen light bulb which may be installed into existing pen light flashlight designs where a truer alignment occurs than that previously possible with conventional pen light bulbs. The present invention substantially fulfills these needs.
In view of the foregoing disadvantages inherent in the known types of pen light bulbs, your applicants have devised a method of providing for a proper alignment of a pen light bulb in conventional pen light flashlights wherein the configuration of the bulb provides for the proper alignment. A self aligning pen light bulb produces a beam of light in response to an introduction of a power flow. The self aligning pen light bulb has a housing, having a first power coupling thereon, a second power coupling, an insulator, a filament and a focusing lens protective element. The housing has a circular body and a circular base. The circular body has an upper extent having an opening thereat. The circular base is positioned distal from the upper extent of the circular body. The circular base is generally planar with an aperture therethrough. The housing has an interior and an exterior with at least a portion of the exterior forming the first power coupling which provides for a passage of the power flow from the exterior to the interior. The housing also has a central axis through the interior of the housing and extending from a central position of the circular base to a central position of the opening at the upper extent. The second power coupling is positioned to extend from the exterior of the circular base and generally aligned with the central axis of the housing. The second power coupling provides for a passage of the power flow to the interior of the housing. The insulator is positioned between the second power coupling and the exterior of the circular base to prevent passage of the power flow between the second power coupling and the exterior of the housing. The filament is in communication with the first power coupling and the second power coupling. The filament produces a light during the introduction of the power flow. The focusing lens protective element has a focusing portion, an upper tapered portion, a lower tapered portion and a mounting portion. The focusing portion has optical qualities to provide for a focusing of the light produced by the filament. The focusing portion is radially disposed about the central axis of the housing distal from the housing. The upper tapered portion is radially disposed about the central axis of the housing and extends from the focusing portion toward the housing. The upper tapered portion has an angle of taper extending outward from the focusing portion toward the housing. The lower tapered portion is radially disposed about the central axis of the housing and extends from the upper tapered portion toward the housing. The lower tapered portion has an angle of taper extending outward from the upper tapered portion toward the housing. The angle of taper of the lower tapered portion is significantly greater than the angle of taper of the upper tapered portion. The mounting portion extends from the lower tapered portion into the interior of the housing.
My invention resides not in any one of these features per se, but rather in the particular combinations of them herein disclosed and it is distinguished from the prior art in these particular combinations of these structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
It is therefore a primary object of the present invention to provide for a self aligning pen light bulb which may be employed in existing pen light flashlights.
Other objects include;
a) to provide for a better seating surface on the transparent protective element of the pen light bulb than that which exists on conventional pen light bulbs.
b) to provide for a wider spring contact surface on the circular base of the pen light bulb than that which exists on conventional pen light bulbs.
c) to provide for a spring contact surface on the circular base of the pen light bulb with a significantly greater area than that which exists on conventional pen light bulbs.
d) to provide for a wider focusing portion on the transparent protective element of the pen light bulb than that which exists on conventional pen light bulbs.
e) to provide for a housing having a circular body with a larger diametric measurement than that which exists on conventional pen light bulbs.
f) to provide for easier manufacture of the pen light bulb by providing for a larger interior of the circular body of the pen light bulb than that which exists on conventional pen light bulbs.
g) to provide for an upper tapered portion and a lower tapered portion on the focusing lens protective element with generally equal lengths along the central axis of the pen light bulb.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated the preferred embodiments of the invention.